Recording of views of objects or scenes or optical images or the like



Sept. 16, 1930.

.J. L. BAIRD RECORDING OF VIEWS OF OBJECTS OR SCENES OR OPTICAL IMAGES OR THE LIKE Filed 'Oct. 7. 1927 dQAiX ZM Patented Sept. 16, 1930 UNITED STATES JOHN LOGIE BAIRD, OF LONDON, ENGLANDIASSIGNOR TO TELEVISION LONDON, ENGLAND, A BRITISH COMPANY PATENT OFFICE LIMITED, or

RECORDING F VIEWS OF OBJECTS OR SCENES OR OPTICAL IMAGES OR THE LIKE Application filed October 7, 1927, Serial No. 224,709, and in Great Britain October 15,

This invention is for improvements in or relating'to the recording of a view of an object or scene, an optical image or the like (hereinafter referred to as the view), and has for its object to provide a novel method and means whereby a convenient and compact I permanent record may be obtained in a form which is easy to handle, store and reproduce.

Various proposals in this direction have been made, all of which consist in making one or more reproductions of the View by some photo-mechanical process, such as a half-tone .or other etching process, in which the variation in optical tones is represented by a variation in the character of the surface, and such variation is used',to produce a varying electric current which is transmitted to the receiving station and reproduced as sound waves which can be recorded on a gramophone or like record. Obviously such methods cannot be used for television, and the present invention provides a method and apparatus which Whilst suitable for television systems, can also be used for reproducing pictures or still views This invention comprises a method of recording a view of an object or the like consisting in exploring it with a light-sensitive electric device (for example a selenium cell) so as to obtain a modulated electric current, converting such current into vibratory movement of a convenient member, and cutting a linear trace of said movement on a record element, in the manner of a gramophone record.

According to another feature of this invention, the method aforesaid also comprises the application of the said modulated current to an electrically-controlled stylus and traversing the stylus relatively to a record to cut therein a linear mechanical record of the said view of the object or the like.

According to a modification of the method aforesaid, the modulated current may be applied to an electric telephone or like soundproducing device, and the sounds produced thereby may be recorded on a gramophone or like record element.

This invention also comprises a record ele ment or a .facsimile reproduction thereof bearing a linear mechanical record of an object or the like, produced by the method above set forth.

In some instances, as for example, when a notable person is delivering a speech, it is desirable to record both a View of the speaker, and a record of the speech, and according to another feature of this invention therefore, a record-element bearing a sight-record as above described may bear also a soundrecord impressed upon it. The sightand sound-records may be impressed upon-opposite sides of a disc-record (like a gramophone record), or when a cylinder is used, they may be spaced apart longitudinally of the cylinder, for example at opposite ends.

This invention also covers a form of record-element in which the soundand sightrecords are formed in parallel spiral grooves on it, Whether it be a disc or a cylinder.

' In yet another modification according to this invention, the sound-record and the sight-record may be made in the same groove on the record-element, one of them bein formed on a side wall or walls thereof an the other on the bottom thereof.

This invention also comprises a method of using a record-element which is prepared in the manner above set forth, consisting in engaging a stylus in the sight-record therein, moving it and the record relatively to one another whereby a vibratory movement of a convenient member, or a sound is produced, converting said vibratory movement or sound into a modulated electric current (for example by means of a microphone) and applying such modulated current to the source of light of a television or like receiver.

In the recording apparatus, it is preferred that the driving mechanism for the record element should be mechanically geared or otherwise so coupled to the exploring mechanism that their relative rates of movement can be readily reproduced, for although the actual rates of movement during the process of recording may be selected at any convenient values, it is important for the reproduction that the ratio should be exactly the same as during the recording; by mechanically gearing the record-element to the exploring device the reproducibility of the ratio of Figure 1 is a diagrammatic representation of apparatus for making a record of a view in accordance with the present invention;

Figure 2 illustrates, also diagrammatically, an alternative form of apparatus;

Figure 3 is a diagrammatic representation of a combined sight and sound record; and

Figure 4: is a dlagram illustratin different methods of forming the record on e recordelement. i

Like reference characters indicate like parts throughout the figures.

Referring first to the arrangement shown in Figure 1, the object whereof a view is to be recorded is indicated by the reference 10. An exploring device comprising a disc with a spiral series of lensed holes is indicated at 11 and a light-interrupting device is shown at 12. A light-sensitive cell is indicated at 13, and the output from this cell is a current modulated in accordance with the object 10.

This current is amplified in amplifiers of any suitable type, indicatedrby the reference 14, and the current from the amplifiers is applied to a recording device 15. Diagrammatically this is indicated as a needle or stylus 16 mounted in a carrier 15 which is subjected to the electromagnetic effects of the amplified current, so that the needle is caused to vibrate. This needle bears on a disc 18 like a gramophone disc, which is kept in rotation so that the needle cuts a spiral groove 17 in accordance with the vibrations imparted to it by the amplified modulated current fromthe cell 13. The record-element 18 and the mode of effecting its cutting may be the same as are used in making a master gramophone record from which duplicates or facsimiles are prepared for sale. In this way a permanent and tangible record of the View of the object 10 is obtained.

It is preferred that the mechanism which rotates the disc 18 should be positively geared with the exploring device 11 so that the ratio of their rates of movement can be readily reproduced. Such connection, however, is not shown in the drawings, as any suitable form may be used, it being appreciated that the exploring devices are usually operated at-a very much higher speedthan the rotationv of the disc 18. w

In the arrangement digrammatically illustrated in Figure 2, the parts 10, 11, 12, 13, 14 are similar to the parts shown in Figure 1, but the amplified modulated current from the cell 13. is applied to a loud-speaking telephone19 or like device, so as to produce sounds equivalent to the record of the object 10, ,These sounds are applied to a microphone 20 from which the current, either directly or amplified,is taken to the recording according-device 22 having a needle23 as indicated in Figure 2, may be arranged to be operative on the disc 18 at the same time.

as the sight-record is made. With the arrangement indicated in Figure 2, it will be appreciated that the microphone 21 must be separated from the microphone 20 by a sound-proof partition 24,. .or alternatively,

the loud-speaker 19 and, its microphone'2 0 may be enclosed in a sound-proof partition.

These sound-proof arrangements, however,

are unnecessary when the arrangement shown in Figure 1 is used.

Figure 3 illustrates diagrammatically a plan of a record-disc 25 which has two rec- 0rd grooves 26, 27 on it,'one of them, say 26, being a sight-record produced by the needle 16 and the other, 27, a sound-record produced by the needle 23. The two grooves are parallel with one another so as t0rCOI1- stitute a double spiral. The starting points of the two records may be made side-by-side or at any select-ed setting, so that for the purpose, of reproducing them absolute synchronism can be assured by appropriately placing the respective needles as hereinafter described. The two grooves, however, need not be side-by-side for they could be arranged on opposite sides of the disc or .in any other desired way, for example at opposite ends of a cylinder.

The mechanical formation of the grooves may take either of two forms illustrated diagrammatically in Figure 4. The disc 28 may be formed with a groove 29 in which the bottom of the groove is cut in an undulating formation by the action of the stylus, or al-.

ternatively, as illustrated at 30, the sides of the groove may be formed by the action of the needle. Since this latter formation is ordinarily used for gramophone disc records, it may be desirable when both sightand sound-records are formed on one disc to'allocate one form of grove to each, namely, that shown at 30 to the sound-record and that shown at 29 to the sight-record.

It also lies within the scope of this invention to combine the two records in a single groove, using the side walls of the groove for, say, the sound-record and the bottom of the groove for the sight-record.

The reproduction of the View which is impressed on the record is eifected by means such as a television receiving device, a needle being applied to the record-track to receive vibration therefrom as when reproducing a gramophone sound-record; this vibration, however, is utilized to modulate a current in accordance with the shape of the track, and the modulated current, amplified if necessary, is applied to the variable-light source of a television receiver.

Various forms of receiver may be used, and these will in general be similar to the receiving apparatus of a television system. Thus, for example, the receiver may'comprise an exploring device which operates in conjunction with a lamp whereof the illumination is caused to vary under the control of the record. A needle or stylus is applied to the record in the usual manner of a gramophone, and the mechanical movement of this needle operates in any convenient manner to vary the voltage applied to a lamp. It may for example operate through a microphonic contact or may be caused to act inductively upon a coil so as to vary the current therein; in'

either case the current variations may be am lified before bein appliedto the lamp.

ny desired form 0 exploring device may be used, and any suitable lamp may be used, such for example as the glow-discharge operation by said sound waves and said associated sound, each of said recording devices including a transmitter, and sound insulating means for isolating said transmitters from each other.

In testimony whereof I aflix my signature.

JOHN LOGIE BAIRD.

lamp described in our British Patent No.

The reproduction of a record which bears both a sight and a sound record is conveniently effected by using two separate needles, and it will be appreciated that in the reproduction it is desirable that these needles should be situated relatively to one another in the same ositions as when the record was made, in order that the two records may be correctly synchronized with one another.

I claim v 1. A method of simultaneously recording a view of an object and an accompanying sound which consists in exploring the object, transforming the light waves obtained by the exploration, first into a modulated electrical current and then into sound waves, and recording the last mentioned sound waves and the accompanying sound simultaneously on a single record receiving member.

2. In apparatus for recording a moving object and associated sound, the combina tion with a light sensitive device for converting light waves into modulated electric current, of means for exploring an object thereby, means adapted for operation by said modulated current for producing sound waves, a record receiving member, and two recording devices for cooperation with said record receiving member, arran ed respectively for operation by said soumI waves and said associated sound.

3. In apparatus for recording a moving object and associated sound, the combination with a light sensitive device for converting l1 ht waves into modulated electric current,

0 means for exploring an object thereby,

means adapted for operation by said modulated current for producing sound waves, a 

